In his speech, Garcetti called L.A. "a place where you can't be pessimistic even if you want to be" and pledged to keep crime in check, boost education and meet with Fortune 500 executives to find new ways to create jobs. Garcetti also spoke of ending runaway production and making Los Angeles more attractive for the entertainment industry.

The oath of office was administered by Kenia Castillo, an eighth-grader at Luther Burbank Magnet Middle School. She said she was 4 when she encountered Garcetti outside City Hall at a Justice For Janitors rally. She attended that event with her mother, a janitor, and more recently volunteered for his mayoral campaign.

Hours before the swearing in, Garcetti signaled that he plans to give former rival Jan Perry a senior role in his administration.

Perry, whose 12 years on the City Council end Sunday, won nearly every precinct in South Los Angeles in the March mayoral primary but did not make it into the May runoff.

“Twelve years of elected service does not mean the end of her service, mark my words,” Garcetti told parishioners at First African Methodist Episcopal Church in South L.A., one of the city's most prominent African American churches, on Sunday. “I’ve got plans for her.”

Perry, the only African American among the top contenders for mayor, declined to comment. She backed Garcetti in his runoff against Wendy Greuel, the city controller.

In his morning appearance, Garcetti cast himself as a champion of the underprivileged.

“I wanted this city to understand that I know the power comes from you, from the least among us, from the most humble, from the forgotten, from those voices and those faces who aren’t even in the pews today,” he said.